Global warming

climate changeglobal climate changeanthropogenic climate change
The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report concluded, "It is that human influence has been the dominant cause of the observed warming since the mid-20th century." The largest human influence has been the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 C-change in a moderate scenario, or as much as 2.6 to 4.8 C-change in an extreme scenario, depending on the rate of future greenhouse gas emissions and on climate feedback effects.

An Inconvenient Truth

Inconvenient TruthA Convenient Causea film starring himself
For Gore's wide-reaching efforts to draw the world's attention to the dangers of global warming which is centerpieced in the film, Al Gore, along with the Intergovernmental Panel on Climate Change (IPCC), won the 2007 Nobel Peace Prize. Gore also received the Prince of Asturias Prize in 2007 for international cooperation. The related album, which featured the voices of Beau Bridges, Cynthia Nixon and Blair Underwood, also won Best Spoken Word Album at the 51st Grammy Awards.

ExxonMobil climate change controversy

ExxonMobilExxonMobilsfunded deniers for years
Bush, ExxonMobil's head lobbyist in Washington wrote to the White House urging that "Clinton/Gore carry-overs with aggressive agendas" be kept out of "any decisional activities" on the US delegation to the working committees of the United Nations' Intergovernmental Panel on Climate Change (IPCC), and recommending their replacement by scientists critical of the prevailing scientific consensus on climate change. The chairman of the IPCC, climate scientist Robert Watson, was replaced by Rajendra K. Pachauri, who was seen as more industry-friendly. A spokesperson for ExxonMobil said the company did not have a position on the chairmanship of the IPCC.

Kyoto Protocol

Climate Change-Kyoto ProtocolKyoto AccordKyoto
The Intergovernmental Panel on Climate Change (IPCC, 2007) have produced a range of projections of what the future increase in global mean temperature might be. The IPCC's projections are "baseline" projections, meaning that they assume no future efforts are made to reduce greenhouse gas emissions. The IPCC projections cover the time period from the beginning of the 21st century to the end of the 21st century. The "likely" range (as assessed to have a greater than 66% probability of being correct, based on the IPCC's expert judgment) is a projected increase in global mean temperature over the 21st century of between 1.1 and 6.4 °C.

Radiative forcing

climate forcingSolar Forcingclimate forcing agents
An alternative table prepared for use in climate model intercomparisons conducted under the auspices of IPCC and including all forcings, not just those of greenhouse gases, is available at Climate sensitivity. Anthropogenic heat. Emission standard. Global warming potential. Sulfate. IPCC glossary. CO2: The Thermostat that Controls Earth's Temperature by NASA's Goddard Institute for Space Studies, October, 2010, Forcing vs. Feedbacks. Intergovernmental Panel on Climate Change’s Fourth Assessment Report (2007), Chapter 2, "Changes in Atmospheric Constituents and Radiative Forcing," pp. 133–134 (PDF, 8.6 MB, 106 pp.).

Runaway greenhouse effect

Hothouse Earthrunaway greenhouserunaway global warming
Climate scientist John Houghton has written that "[there] is no possibility of [Venus's] runaway greenhouse conditions occurring on the Earth". The IPCC (Intergovernmental Panel on Climate Change) has also stated that "a 'runaway greenhouse effect'—analogous to [that of] Venus—appears to have virtually no chance of being induced by anthropogenic activities." However, climatologist James Hansen disagrees. In his Storms of My Grandchildren he says that burning coal and mining oil sands will result in runaway greenhouse on Earth.

Emission intensity

carbon intensityemission factorcarbon-intensive
The UNFCCC has accepted the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories, developed and published by the Intergovernmental Panel on Climate Change (IPCC) as the emission estimation methods that must be used by the parties to the convention to ensure transparency, completeness, consistency, comparability and accuracy of the national greenhouse gas inventories. These IPCC Guidelines are the primary source for default emission factors. Recently IPCC has published the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. These and many more greenhouse gas emission factors can be found on IPCC's Emission Factor Database.


Earth's surfaceterrestrialworld
This last phenomenon is known as the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the ground, thereby raising the average temperature. Water vapor, carbon dioxide, methane, nitrous oxide, and ozone are the primary greenhouse gases in the atmosphere. Without this heat-retention effect, the average surface temperature would be −18 C, in contrast to the current +15 C, and life on Earth probably would not exist in its current form. In May 2017, glints of light, seen as twinkling from an orbiting satellite a million miles away, were found to be reflected light from ice crystals in the atmosphere.

George W. Bush

BushPresident BushPresident George W. Bush
During his campaign, Bush criticized his Democratic opponent, incumbent Vice President Al Gore, over gun control and taxation. When the election returns were tallied on November 7, Bush had won 29 states, including Florida. The closeness of the Florida outcome led to a recount. The initial recount also went to Bush, but the outcome was tied up in lower courts for a month until eventually reaching the U.S. Supreme Court. On December 9, in the controversial Bush v.


ozonationO 3 ozone generator
Ozone acts as a greenhouse gas, absorbing some of the infrared energy emitted by the earth. Quantifying the greenhouse gas potency of ozone is difficult because it is not present in uniform concentrations across the globe. However, the most widely accepted scientific assessments relating to climate change (e.g. the Intergovernmental Panel on Climate Change Third Assessment Report) suggest that the radiative forcing of tropospheric ozone is about 25% that of carbon dioxide. The annual global warming potential of tropospheric ozone is between 918–1022 tons carbon dioxide equivalent/tons tropospheric ozone.


deforestedland clearingforest clearing
Deforestation is a contributor to global warming, and is often cited as one of the major causes of the enhanced greenhouse effect. Tropical deforestation is responsible for approximately 20% of world greenhouse gas emissions. According to the Intergovernmental Panel on Climate Change deforestation, mainly in tropical areas, could account for up to one-third of total anthropogenic carbon dioxide emissions. But recent calculations suggest that carbon dioxide emissions from deforestation and forest degradation (excluding peatland emissions) contribute about 12% of total anthropogenic carbon dioxide emissions with a range from 6% to 17%.

Renewable energy

renewablesrenewable energiesrenewable
The Intergovernmental Panel on Climate Change has said that there are few fundamental technological limits to integrating a portfolio of renewable energy technologies to meet most of total global energy demand. Renewable energy use has grown much faster than even advocates anticipated. At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply. Also, Professors S. Pacala and Robert H.

Positive feedback

positive feedback looppositiveexacerbated
Other examples of positive feedback subsystems in climatology include: The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report states that "Anthropogenic warming could lead to some effects that are abrupt or irreversible, depending upon the rate and magnitude of the climate change." A self-fulfilling prophecy is a social positive feedback loop between beliefs and behavior: if enough people believe that something is true, their behavior can make it true, and observations of their behavior may in turn increase belief. A classic example is a bank run. Another sociological example of positive feedback is the network effect.

Environmental activism of Al Gore

environmentalenvironmental activist movement
Al Gore is a United States politician and environmentalist. He is the former Vice President of the United States (1993–2001), the 2000 Democratic Party presidential nominee, and the co-recipient of the 2007 Nobel Peace Prize with the Intergovernmental Panel on Climate Change. He has been involved with the environmental activist movement for a number of decades, and has had full participation since he left the vice-presidency in 2001.

Atmospheric methane

methanemethane cyclemethane in the atmosphere
The Intergovernmental Panel on Climate Change does not adequately account for arctic methane in permafrost. Slightly over half of the total emission is due to human activity. Since the Industrial Revolution humans have had a major impact on concentrations of atmospheric methane, increasing atmospheric concentrations roughly 250%. Conversion of forests and natural environments into agricultural plots increases the amount of nitrogen in the soil, which inhibits methane oxidation, weakening the ability of the methanotrophic bacteria in the soil to act as sinks. Additionally, by changing the level of the water table, humans can directly affect the soil's ability to act as a source or sink.

United States Environmental Protection Agency

Environmental Protection AgencyEPAU.S. Environmental Protection Agency
These reduce the use or creation of hazardous chemicals, save water, and reduce greenhouse gas release. The Section 404 Program regulates the discharge of dredged or fill material into waters of the United States. Permits are to be denied if they would cause unacceptable degradation or if an alternative doesn't exist that does not also have adverse impacts on waters. Permit holders are typically required to restore or create wetlands or other waters to offset losses that can't be avoided. The State Revolving Loan Fund Program replaced the Construction Grants Program, which was phased out in 1990.

Renewable energy commercialization

Renewable energy policyRenewable energy commercialisationRenewable energy development
In the Intergovernmental Panel on Climate Change's reviews of scenarios of energy usage that would keep global warming to approximately 1.5 degrees, the proportion of primary energy supplied by renewables increases from 15% in 2020 to 60% in 2050 (median values across all published pathways). The proportion of primary energy supplied by biomass increases from 10% to 27%, with effective controls on whether land use is changed in the growing of biomass. The proportion from wind and solar increases from 1.8% to 21%. At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply. Mark Z.

Public opinion on global warming

Public opinion on climate changepublicpublic opinion
For example, Margaret Thatcher, never a friend of the coal mining industry, was a strong supporter of an active climate protection policy and was instrumental in founding the Intergovernmental Panel on Climate Change and the British Hadley Centre for Climate Prediction and Research. Some speeches, as to the Royal Society on 27 September 1988 and to the UN general assembly in November 1989 helped to put climate change, acid rain, and general pollution in the British mainstream. After her career, however, Thatcher was less of a climate activist, as she called climate action a "marvelous excuse for supranational socialism", and called Al Gore an "apocalyptic hyperbole".

National Academy of Sciences

United States National Academy of SciencesNational Academy of ScienceU.S. National Academy of Sciences
The Academy gives a number of different awards: In 2005, the national science academies of the G8 forum (including the National Academy of Sciences) and science academies of Brazil, China, and India (three of the largest emitters of greenhouse gases in the developing world) signed a statement on the global response to climate change. The statement stresses that the scientific understanding of climate change had become sufficiently clear to justify nations taking prompt action. On May 7, 2010, a letter signed by 255 Academy members was published in Science magazine, decrying "political assaults" against climate change scientists.

Republican Party (United States)

RepublicanRepublican PartyR
In 2006, then-California Governor Arnold Schwarzenegger broke from Republican orthodoxy to sign several bills imposing caps on carbon emissions in California. Then-President George W. Bush opposed mandatory caps at a national level. Bush's decision not to regulate carbon dioxide as a pollutant was challenged in the Supreme Court by 12 states, with the court ruling against the Bush administration in 2007. Bush also publicly opposed ratification of the Kyoto Protocols which sought to limit greenhouse gas emissions and thereby combat climate change; his position was heavily criticized by climate scientists. The Republican Party rejects cap-and-trade policy to limit carbon emissions.

Joe Barton

Joe L. BartonBarton, JoeRepresentative Joe Barton
During former Vice President Al Gore's testimony to the Energy and Commerce Committee in March 2007, Barton asserted to Gore that "You're not just off a little, you're totally wrong" (climate scientists have refuted Barton's assertion ), stating that "Global warming science is uneven and evolving." Upset with House Speaker Nancy Pelosi's passage of global warming legislation in 2009, he said: "You can't regulate God."

Physical impacts of climate change

environmentphysicalphysical effects of global warming
This large-scale pattern of change is a robust feature present in nearly all of the simulations conducted by the world's climate modeling groups for the 4th Assessment of the Intergovernmental Panel on Climate Change (IPCC), and is also evident in observed 20th century precipitation trends. Changes in regional climate are expected to include greater warming over land, with most warming at high northern latitudes, and least warming over the Southern Ocean and parts of the North Atlantic Ocean.

Environmental impact of meat production

Environmental effects of meat productionanimal agriculturedetrimental environmental effects of meat production
Using a different sectoral assignment of emissions, the IPCC (Intergovernmental Panel on Climate Change) has estimated that agriculture (including not only livestock, but also food crop, biofuel and other production) accounted for about 10 to 12 percent of global anthropogenic greenhouse gas emissions (expressed as 100-year carbon dioxide equivalents) in 2005 and in 2010. A PNAS model showed that even if animals were completely removed from US agriculture, US GHG emissions would be decreased by 2.6% (or 28% of agricultural GHG emissions).

Emissions trading

cap and tradecap-and-tradeemissions trading scheme
In 1990, the first Intergovernmental Panel on Climate Change (IPCC) report highlighted the imminent threat of climate change and greenhouse gas emission, and diplomatic efforts began to find an international framework within which such emissions could be regulated. In 1997 the Kyoto Protocol was adopted. The Kyoto Protocol is a 1997 international treaty that came into force in 2005. In the treaty, most developed nations agreed to legally binding targets for their emissions of the six major greenhouse gases.


veganvegansvegan diet
A 2017 study published in the journal Carbon Balance and Management found animal agriculture's global methane emissions are 11% higher than previous estimates based on data from the Intergovernmental Panel on Climate Change. A 2018 study found that global adoption of plant-based diets would reduce agricultural land use by 76% (3.1 billion hectares, an area the size of Africa) and cut total global greenhouse gas emissions by 28% (half of this emissions reduction came from avoided emissions from animal production including methane and nitrous oxide, and half came from trees re-growing on abandoned farmland which remove carbon dioxide from the air).